#include<bits/stdc++.h>
using namespace std;
int n = 4000;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	freopen("after.in","w",stdout);
	cout << n << "\n";
	for(int i = 1;i <= n;i++)
		cout << i << " ";
	cout << "\n";
	return 0;
}
